The present invention generally relates to region extraction apparatuses, region extraction methods and computer readable recording mediums, and more particularly to a region extraction apparatus which extracts a desired region from a moving image, a region extraction method employed in such a region extraction apparatus, and a computer readable recording medium which stores a program for causing a computer to extract the desired region from the moving image.
Recently, due to the developments made in the image synthesizing technology, there are increased demands to carry out a process of extracting (or cutting out) a region of an object or the like specified by a user from a moving image. When extracting only a desired object from the moving image, it is necessary to extract the desired object from each frame of the moving image, and a method of manually extracting the desired object is too time-consuming from the practical point of view. Accordingly, there are demands to realize a method of extracting a region of the object or the like specified by the user from the moving image at a high speed, without the need for a manual process.
Conventionally, there is a method of extracting the desired object from the moving image by use of a totally manual extraction tool. The totally manual extraction tool is similar to a picture drawing tool provided with respect to a still picture, and carries out a process of specifying and extracting a contour of a desired object from the still picture, and carrying out this process with respect to all of the frames of the moving image.
FIG. 77 is a diagram for explaining an image extracting operation using a totally manual extraction tool.
As shown in FIG. 77(A), an image 200 prior to an extraction is displayed on a display 120 which is coupled to a computer 110, and a user extracts a desired object 210 from the image by use of an input device 130 such as a mouse and a pen while monitoring the image 200. For example, the user extracts the desired object 210 by tracing a contour line of the object 210 and specifying a closed curved surface. Even in the case of a moving image wherein relatively similar images repeat as shown in FIG. 77(B), the operation of extracting a region is carried out similarly to that with respect to the still picture but with respect to all of the frames of the moving image.
When using the totally manual extraction tool, the operation shown in FIG. 77 must be carried out with respect to the images of all of the frames forming the moving image, and the operation is time consuming. For this reason, there are demands to realize a system which can minimize the number of required manual instructions.
For example, Japanese Laid-Open Patent Applications No.5-14807 and No.8-185540 propose image region extraction apparatuses which reduce the number of required manual instructions when extracting the desired object from the moving image.
According to the moving image region extraction apparatus proposed in the Japanese Laid-Open Patent Application No.5-14807, boundaries of regions are manually specified with respect to the first 2 fields. With respect to the third and subsequent fields, the shapes of the boundaries in the present field are predicted from a change in the shape of the boundary of a significant region in the first 2 fields, and the desired region is extracted based on the predicted shapes of the boundaries in the present field.
On the other hand, according to the specific region extraction apparatus proposed in the Japanese Laid-Open Patent Application No.8-185540, a first specific region is extracted from an input image signal of the moving image based on a predetermined threshold value. A noise region is eliminated from the extracted first specific region based on a predetermined specific pattern, and a second specific region which interpolates a missing part is extracted. By comparing the second specific region of the previous frame stored in a memory and the second specific region of the present input image, a third specific region is extracted as a specific region which is to be extracted.
But when extracting the desired object from the moving image using the totally manual extraction tool, it is necessary to extract the desired object in each frame, and there as a problem in that an extremely large amount of manual operation is required to extract the desired object.
In addition, according to the apparatus proposed in the Japanese Laid-Open Patent Application No.5-14807, no correction is made with respect to the extracted image, and there was a problem in that an accurate region extraction cannot be made since it is impossible to cope with the deformation of the original image.
Furthermore, according to the apparatus proposed in the Japanese Laid-Open Patent Application No.8-185540, the second specific region of the previous frame stored in the memory and the second specific region of the present input image are simply compared to extract the third specific region as the specific region which is to be extracted. As a result, there was a problem in that an accurate region extraction cannot be made.
Accordingly, it is a general object of the present invention to provide a novel and useful region extraction apparatus, region extraction method and computer readable recording medium, in which the problems described above are eliminated.
Another and more specific object of the present invention is to provide a region extraction apparatus, a region extraction method and a computer readable recording medium which can automatically and accurately extract a desired object from a moving image.
Still another object of the present invention is to provide a region extraction apparatus for extracting a desired region from a moving image, comprising region specifying means for specifying contour points of a region which is to be extracted, template creating means for creating a template of the region which is to be extracted based on the contour points of the region specified by the region specifying means, template matching means for matching the template created by the template creating means and the moving image, and template correcting means for correcting the template depending on a matching result obtained by the template matching means. According to the region extraction apparatus of the present invention, it is possible to accurately extract only the desired region from the moving image.
A further object of the present invention is to provide a region extraction apparatus for extracting a desired region from each frame of a moving image based on an example, comprising contour extracting means for extracting a contour part of the example corresponding to a contour part of the desired region, region judging means for judging whether the contour part of the example extracted by the contour extracting means falls inside or outside the contour part of the desired region, and correcting means for correcting the desired region depending on a judgement result of the region judging means. According to the region extraction apparatus of the present invention, an error or difference from the example is corrected in each frame, and only the desired region is accurately extracted from the moving image.
Another object of the present invention is to provide a region extraction apparatus for extracting a desired region from a moving image, comprising region extracting means for extracting the desired region from each frame of the moving image, and correcting means for correcting an erroneous region of the desired region of each frame already extracted by the region extracting means. According to the region extraction apparatus of the present invention, it is possible to accurately extract only the desired region from the moving image because an error generated in each frame which is already extracted is corrected.
Another object of the present invention is to provide a region extraction apparatus for extracting a desired region from a moving image, comprising region extracting means for extracting the desired region depending on a region of an example, deformation detecting means for detecting a deformation of the region extracted by the region extracting means from the region of the example, and correcting means for correcting the region extracted by the region extracting means depending on an amount of the deformation detected by the deformation detecting means. According to the region extraction apparatus of the present invention, the deformation from the example is corrected in each frame by correcting the region depending on the amount of change from the example, and thus, it is possible to accurately extract only the desired region from the moving image.
Still another object of the present invention is to provide a region extraction apparatus comprising difference detecting means for detecting a difference between an extracting object which is to be extracted and a background, and contour extracting means for extracting a part with the difference detected by the difference detecting means smaller than a predetermined difference as a contour. According to the region extraction apparatus of the present invention, it is possible to efficiently make the correction by not making the correction with respect to a part where the difference is small and a correction is unnecessary.
A further object of the present invention is to provide a computer readable recording medium which stores a program for causing a computer to extract a desired region from a moving image, comprising region specifying means for making the computer specify contour points of a region which is to be extracted, template creating means for making the computer create a template of the region which is to be extracted based on the contour points of the region specified by the region specifying means, template matching means for making the computer match the template created by the template creating means and the moving image, and template correcting means for making the computer correct the template depending on a matching result obtained by the template matching means. According to the computer readable recording medium of the present invention, it is possible to accurately extract only the desired region from the moving image.
Another object of the present invention is to provide a computer readable recording medium which stores a program for causing a computer to extract a desired region from each frame of a moving image based on an example, comprising contour extracting means for making the computer extract a contour part of the example corresponding to a contour part of the desired region, region judging means for making the computer judge whether the contour part of the example extracted by the contour extracting means falls inside or outside the contour part of the desired region, and correcting means for making the computer correct the desired region depending on a judgement result of the region judging means. According to the computer readable recording medium of the present invention, an error or difference from the example is corrected in each frame, and only the desired region is accurately extracted from the moving image.
Still another object of the present invention is to provide a computer readable recording medium which stores a program for causing a computer to extract a desired region from a moving image, comprising region extracting means for making the computer extract the desired region from each frame of the moving image, and correcting means for making the computer correct an erroneous region of the desired region of each frame already extracted by the region extracting means, According to the computer readable recording medium of the present invention, the deformation from the example is corrected in each frame by correcting the region depending on the amount of change from the example, and thus, it is possible to accurately extract only the desired region from the moving image.
A further object of the present invention is to provide a computer readable recording medium which stores a program for causing a computer to extract a desired region from a moving image, comprising region extracting means for making the computer extract the desired region depending on a region of an example, deformation detecting means for making the computer detect a deformation of the region extracted by the region extracting means from the region of the example, and correcting means for making the computer correct the region extracted by the region extracting means depending on an amount of the deformation detected by the deformation detecting means. According to the computer readable recording medium of the present invention, it is possible to accurately extract only the desired region from the moving image because an error generated in each frame which is already extracted is corrected.
Another object of the present invention is to provide a computer readable recording medium which stores a program for causing a computer to extract a contour, comprising difference detecting means for making the computer detect a difference between an extracting object which is to be extracted and a background, and contour extracting means for making the computer extract a part with the difference detected by the difference detecting means smaller than a predetermined difference as a contour. According to the computer readable recording medium of the present invention, it is possible to efficiently make the correction by not making the correction with respect to a part where the difference is small and a correction is unnecessary.
Still another object of the present invention is to provide a region extraction method for extracting a desired region from a moving image, comprising a region specifying step specifying contour points of a region which is to be extracted, a template creating step creating a template of the region which is to be extracted based on the contour points of the region specified by the region specifying step, a template matching step matching the template created by the template creating step and the moving image, and a template correcting step correcting the template depending on a matching result obtained by the template matching step. According to the region extraction method of the present invention, it is possible to accurately extract only the desired region from the moving image.
A further object of the present invention is to provide a region extraction method for extracting a desired region from each frame of a moving image based on an example, comprising a contour extracting step extracting a contour part of the example corresponding to a contour part of the desired region, a region judging step judging whether the contour part of the example extracted by the contour extracting step falls inside or outside the contour part of the desired region, and a correcting step correcting the desired region depending on a judgement result of the region judging step. According to the region extraction method of the present invention, an error or difference from the example is corrected in each frame, and only the desired region is accurately extracted from the moving image.
Another object of the present invention is to provide a region extraction method for extracting a desired region from a moving image, comprising a region extracting step extracting the desired region from each frame of the moving image, and a correcting step correcting an erroneous region of the desired region of each frame already extracted by the region extracting step. According to the region extraction method of the present invention, the deformation from the example is corrected in each frame by correcting the region depending on the amount of change from the example, and thus, it is possible to accurately extract only the desired region from the moving image.
Still another object of the present invention is to provide a region extraction method for extracting a desired region from a moving image, comprising a region extracting step extracting the desired region depending on a region of an example, a deformation detecting step detecting a deformation of the region extracted by the region extracting step from the region of the example, and a correcting step correcting the region extracted by the region extracting step depending on an amount of the deformation detected by the deformation detecting step. According to the region extraction method of the present invention, it is possible to accurately extract only the desired region from the moving image because an error generated in each frame which is already extracted is corrected.
A further object of the present invention is to provide a region extraction method comprising a difference detecting step detecting a difference between an extracting object which is to be extracted and a background, and a contour extracting step extracting a part with the difference detected by the difference detecting step smaller than a predetermined difference as a contour. According to the region extraction method of the present invention, it is possible to efficiently make the correction by not making the correction with respect to a part where the difference is small and a correction is unnecessary.